Although there are sites that cater specifically to photo-blogs (or simply, photo gallery sites like PBASE, Flickr - the distinction b/w photo-gallery vs photo-blog is blurring..), the trend now is to host your photos (and movies too!) on blogging platforms such as Wordpress and Blogger.
FWIW, if you do not have any blog or photo-gallery, suggest you start with a blog on Blogger. I prefer blogger over wordpress coz the latter has security flaws (altho' constantly patched / updated as new security holes / flaws are discovered) that made it easy for hackers to access individual sites.
You will also need a site to host your photos -- tried several photo hosting sites b4 i settled on picassa. Some considerations for choosing a good host: bandwidth - some hosts are always congested and getting yr photos linked to / displayed on yr blog take ages, some hosts limit the max size of yr photos to 300x400px - I prefer as large as possible, limited by screen size and resolution ! And of course, must be f-r-e-e !
In the old days, if you are a commercial photographer, you only need excellent camera skills, the labs took care of all the analog / film processing, retouching and printing.
Today, if you want to earn your keep thro photography, besides good camera skills and knowledge, you also need to be computer savvy and technically competent in photoshop, d.a.m., some coding skills, and of course, blogging and having your web gallery!
Good luck to all aspiring commercial / wedding photographers!